The present invention refers to a teatcup liner adapted to be mounted in a shell to form a teatcup to be applied to a teat of an animal, the teatcup liner defining an inner space for receiving the teat and including a primary component forming an upper head of the teatcup liner and a secondary component forming a lower barrel of the teatcup liner, the primary component including a primary peripheral portion, a primary connecting ring extending downwardly from the primary peripheral portion, and a lip extending inwardly from the primary peripheral portion and defining an opening for the introduction of the teat, the secondary component including a secondary peripheral portion and a secondary connecting ring extending upwardly from the secondary peripheral portion, and the primary component being connectable to the secondary component for realising the teatcup liner by an engagement of the primary connecting ring to the secondary connecting ring.
Furthermore, the present invention refers to a teatcup liner as defined in the preamble of claim 19. The present invention also refers to a teatcup as defined in claim 29.
Teatcup liners are typically manufactured in a natural or synthetic rubber material. Rubber materials have many advantages connected to the elastic properties of rubber. These elastic properties are advantageous both during the manufacturing of the teatcup liner and during milking. The teatcup liner formed in a mould can easily be removed from the mould and the core shaping the inner space of the teatcup liner after the vulcanisation. However, the vulcanisation of the rubber requires a significant vulcanisation time before the rubber can be removed from the mould and the core. This is a limiting factor in the manufacturing of teatcup liners. It is desirable to be able to shorten the vulcanisation time.
In order to speed up the manufacturing process, it is proposed to manufacture teatcup liners in a plastic material, i.e. Thermo Plastic Elastomers, TPE. The solidification time needed after moulding of such a plastic material is significantly shorter than the vulcanisation time needed for a rubber material. Consequently, by using such a thermoplastic material in the teatcup liner it would be possible to speed up the manufacturing thereof. A further advantage of a thermoplastic material is that it may be re-used. However, the elasticity of thermoplastic materials is generally smaller than the elasticity of rubber, which means that a teatcup liner with a conventional design would be difficult to remove from the mould, and in particular the from core, after the solidification.
The inventors have realised that a higher flexibility regarding the selection of material or materials in the teatcup liner may be achieved if the teatcup liner is manufactured as a number of separate components, which are then connected to each other when the teatcup liner is mounted. However, such a teatcup liner would then include a joint between adjoining components. It is important that such a joint is designed in such a way that it is tight, preventing any leakage of air or milk, and preventing dirt and milk residuals from penetrating the joint, where they may promote bacterial growth.
DE-A-199 49 151 discloses a teatcup of the kind initially defined. The teatcup includes a teatcup liner and a shell. The teatcup liner includes a first component forming a head portion and a second component forming a barrel portion. The first and second components are joined to each other by means of a snap joint or a thread joint so that either one of them can be changed when so required. The teatcup liner of this prior art document is mounted in a shell, wherein the barrel portion is positioned in the shell. The barrel portion has lower end gripped by a lower end of the shell, and an upper end extending over the upper end of the shell. The head portion forms a separate part connectable to the assembly of the shell and the barrel portion. No particular measures have been taken to obtain a reliable and tight sealing between the head portion and the barrel portion.